青少年的7特斯拉飞行时间磁共振血管造影

7 Tesla Time-of-Flight MRA in Adolescents.

作者信息

Valencia Sergio, Machado-Rivas Fedel, Cortes-Albornoz Maria Camila, Cartmell Samuel Cd, Griffin Harry, Orbach Darren B, Rameh Vanessa, See Alfred Pokmeng, Warfield Simon K, Afacan Onur, Jaimes Camilo

机构信息

From the Department of Radiology (S.V., F.M.-R., M.C.C.-A., S.C., H.G., C.J.), and the Pediatric Imaging Research Center (S.V., F.M.-R., M.C.C.-A., C.J.), Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA; Department of Neurointerventional Radiology (D.B.O., A.P.S.), and Department of Radiology (V.R., S.K.W., O.A.), Computational Radiology Laboratory (S.K.W., O.A.), Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.

出版信息

AJNR Am J Neuroradiol. 2025 Jul 1. doi: 10.3174/ajnr.A8908.

DOI:10.3174/ajnr.A8908

PMID:40592541

Abstract

BACKGROUND AND PURPOSE

The increased signal-to-noise ratio (SNR) at 7 Tesla (7T) enables higher spatial resolution for neurovascular imaging, yet its application in pediatric magnetic resonance angiography (MRA) remains underexplored. This study systematically evaluates the advantages of 7T time-of-flight (TOF) MRA compared to 3T in pediatric patients, hypothesizing that 7T would provide superior vessel contrast and increased vascular volume, given the use of smaller voxels, as well as higher SNR, despite these smaller voxels.

MATERIALS AND METHODS

This HIPAA-compliant, IRB-approved retrospective study included pediatric patients (<19 years) who underwent 7T TOF MRA. Controls consisted of either same-subject 3T MRAs within 6 months (when available) or age-and sex-matched 3T MRA subjects. Imaging parameters were optimized for spatial resolution at 7T to achieve 0.3-0.4 mm isotropic voxels. Quantitative analysis included contrast ratio (CR) and SNR measurements for the ICA, M1 to M4 arterial segments, and lenticulostriate perforating arteries. Vascular volume was assessed using 3D segmentation. Semiquantitative vessel conspicuity ratings and motion artifact scoring were performed by blinded neuroradiologists.

RESULTS

Fifteen patients (10 with 7T MRA, 5 with matched 3T controls) and 20 MRAs were analyzed. CR was significantly higher at 7T for perforators, M3, and M4 branches (P < 0.05), with the greatest improvement in M4 branches. Vascular volume was 147% greater at 7T (P = 0.018), reflecting improved small vessel depiction and segmentation. Semiquantitative analysis showed significantly better vessel conspicuity at 7T for M4 branches and lenticulostriate perforators (P < 0.01). Motion artifact scores were similar between field strengths (P = 0.118).

CONCLUSIONS

7T TOF MRA significantly enhances vascular contrast and improves visualization of small arteries compared to 3T, making it a valuable tool for pediatric cerebrovascular imaging.

ABBREVIATIONS

CR＝ Contrast Ratio; LSA＝ Lenticulostriate Perforating Arteries.

摘要

背景与目的

7特斯拉（7T）时信噪比（SNR）的提高使得神经血管成像能够获得更高的空间分辨率，但其在儿科磁共振血管造影（MRA）中的应用仍未得到充分探索。本研究系统评估了7T时间飞跃（TOF）MRA与3T相比在儿科患者中的优势，假设尽管体素较小，但由于使用了较小的体素以及更高的SNR，7T将提供更好的血管对比度和增加的血管容积。

材料与方法

这项符合HIPAA规定、经机构审查委员会（IRB）批准的回顾性研究纳入了接受7T TOF MRA检查的儿科患者（<19岁）。对照组包括6个月内同一受试者的3T MRA（如有）或年龄和性别匹配的3T MRA受试者。对成像参数进行了优化，以在7T时实现0.3 - 0.4毫米各向同性体素。定量分析包括对颈内动脉（ICA）、M1至M4动脉段以及豆纹状穿支动脉的对比度比值（CR）和SNR测量。使用三维分割评估血管容积。由不知情的神经放射科医生进行半定量血管显影评分和运动伪影评分。

结果

分析了15例患者（10例进行了7T MRA，5例有匹配的3T对照）和20次MRA检查。7T时穿支动脉、M3和M4分支的CR显著更高（P < 0.05），M4分支改善最为明显。7T时血管容积增加了147%（P = 0.018），反映出小血管描绘和分割得到改善。半定量分析显示，7T时M4分支和豆纹状穿支动脉的血管显影明显更好（P < 0.01）。不同场强之间的运动伪影评分相似（P = 0.118）。